Jack for dead-end insulators



T. F. JOHNSON, JR

JACK FOR DEAD END INSULATORS Filed Aug. 12. 1922 5 A'2 sheets-sheet 1 T. F. JOHNSON. JR

'JACK FOR DEAD END INSULATORS @ch 30,1923. www@ Filed Aug. 12. 1922 2 Sheetshee 2 Jb/Lmsom, Jr,

INVENTOR,

WITNESSES l jack screws,

deprcciate faster and must- 0 to take up Patentes oei. so, 1912s.

iran stai' V'rOMLINsON FORT JOHNSON, an., Or ATLANTA, GEORGIA.

JACK F03 :DEAD-END INSULATORS.

. Application filed August 12, 1922. Serial No. 581,452.

To all w/zom t may] concern.'

Be it known that l. TOMLTNSONF. soN.V`v Jr., a citizen of the United residing at litlauta,

JOHN- States, in the county or' 4Fulton 5 and State of Georgia7 haverinvented new and useful End Insulators, of which the following is a specification. i

This invention relates to improvements in and particularly to jacks designed to be used inthe changing of dead end insulators for high voltage transmission lin-es. y

It is well known that dead end insulators be ofteuer than other types of insulators. When dead end insulators must be renewed the ordina-ry method is to shut down the transmission line, and by means of rope tackle( 20 take the strain oir the line oil the detective insulator so that it can be removed. Another method. usable on livev lines. employs a short insulating tension rod rope tackle7 the rod being placed, between the tackle and the come-along. The rope tackle takes up a great deal oi space, therefore limit-ing the length of the insulating rod to 2 feet or less. Since it is possible to reach only a limited distance out on the` trans'- mission line when placing the come-along, the combination otrope tackle and rod becomes prohibitively dangerous Vwhen the volt-age of the line is high. Thus with known apparatus following` known methods it is absolutely impossible to change dead end insulators safely on live'transmission lines carrying more than.66.000 volts.

Another disadvantage of rope tackle is that when the men are pulling on the rope a heavyload (some conductors have a tension of 10.000 lbs.) the rhythmic jerks start,oscillationsv of the line. which are dangerous because the Vline is liable to swingV intoV contacty withl another'live line ol" the system and burnV out the circuit. again. the ica-ll rope ot the tackle may slip through the hands of the 'workmen and al ways must be tiedat the finish 'of the pull. Futhermore. the'rope is continually'stretch# ing and in the course of time becomes rotten andmust be renewed. l

"In accordance with the present invention. ajack is provided to take the tension ott' insulators. by means of'which a single workman can exert a pull of 10,000 llos., whereas improvements in .lacks for Dead-Y Vor more, since an replaced in combination with` live or siX men would be needed to pull that much with tackle. The jack does the pullingv `grachtally and smoothly without jerking and hence oscillations of the line are not set up; and there is never any danger of slipping or breaking. By employing` one of my jacks, the maintenance crew can change dead end insulators on live lines carrying 300,000 volts insulating` stick five feet in length or longer may he easily handled.

The liack cannotwear out; it is lighter and more easily carried than tackle; it is more quickly mounted on` the tower or pole and more readily put in operation;

The invention has other aims and advantages which will appear from the following description of a preferred embodiment thereof.

In the accompanying drawings forming a part of this specification, there is shown, by wayof illust-ration, a jack constructed in accordance with the invention, whereinz.

Fie'ure l is an elevation showing the jack in operation on a transmission tower; Figure 2 is a sectional elevation of the jack; i A

Figure 3 is an elevation of the same looking from the right side oi" Figure 2;

` Figure l is a diametric sectional view or' the housingor casing of the jack.

Figure 5 is an end Figure 6 is an end elevation ofthe nut of the jack;

` Figure 7 is a diametric section of the same;

vFigure 8 is a plan of the washer which retains the nutin place.

Referring more speciicallyto the illustrative embodiment Oi" the invention shown in the drawing, there appears, as best shown in Figures 2 and 3, a clamp l0 of any well known form mounting the jack proper and adapted to hold said jack on a cross arm 4oi a pole, on a tower (as seen in Fig. 1) or other support. One arm of the clamp 10 carries or is formed into a pair of spaced Yflanges. conveniently provided by a section of a channel barrer else two angle bars 1l bolted or riveted to said arm and'extending at right angles, as shown Figure 2. Preferably the two flanges are' bored sothat a pin 12 may be'inserted through the bores to turn axially therein and form a swivel connection between the jack and the supportine clamp. The head 13 of the pin is elevation of the same;

' i Obviously bored to receive a bolt or `the like 14,.which also is passed through the ends of a U-sliaped strap embracing the hollow casing or housing 16 of the jack. This casing has ears 17 with perioratlions (Fig. 4) 'torthe bolt 14. The arrangement is such thatthe casing may swing about boltH 14 as an axis, and also about the axis of pin 12; `or in other words, the jack is mounted to move in two planes at vright angles. jacktobe used in replacing two dead end insulators without changing the position ot theclamp. (See Fig. 1.) Y

there are many constructions other than the Vone illustrated by means ot which the jack may be secured upon a cross arm or the like to swing in two planes, the invention is not limited to the jack mountingshown.

rlhe housing 16 is formed sojtliat for particular .about one-hall of its length a cup-like rien l n a s cess 1s provided within which a thrust ball bearing 18 isheld, as shown in Fig. 2. A nut member 19 whose construction is clearly shown in Figs. 6 and 7, is held within the casing or housing` 16 by a disk or washer 20, shown separately in Fig. 8. The washer 20 is held against rotation by radially extending screws 21, while the nut 19'is freely rotatable between the washer and the ball bearing. One end of the nut has a neck 22 which protrudes out of the-casing and a radial lug 23l is formed on said neck, asrshownQ The nut is internally screw threaded to engage with a threaded steel rod 24 having' a'clevis 25 or the like on one end. Rod 24 extends through the casing 16 as shown; The clevis provides convenient means Vby which the 'j ack screw may be connected 'with the transmission line. In order to turn the Vnut 19 and thus move 4rod 24 longitudinally to exert a pull, a wheel or sheave 26 is mounted on the neck 22. Preferably the hub of the sheave has a slot 27 of a size to pass the lug 23 on the neck 22, and a rib 28 adapted to engage against the lug 23 after thel fsheave is in position and has lbeen turned. The construction permits easy and rapid removal of the sheave and the substitution of a sired;

larger 4or smaller sheave ifi de# A l Referring now to Fig. 1, there the jack is l shown in the act ot taking the load ot line stick or rod 34 also carries a 29 ofi the-dead end insulators 30 supported upon a towel` 31. The iack is clamped upon the cross arm 32 of the tower. In order to make. elevation of the jack to the cross arm easier, a clevis 33 is pivoted to the casing 16 of the jack.

the'hook of the insulating stick 34, supported from aboveV during coupling and un`cou lpling by a rope 35. The other end of the with a come-along 36 gripping the transmission line 29.

This enables the andl i Va transmission line,

The clevis 25 is connected with y hook vengaged i llliorder to ,turn the sheave; l26 and` thus transfer the tension of thefline to theijack, a rope 37 passes over the sheave and is re-V ceived within theV peripheral" groove thereof as shown. @ne end of this rope may be secured .to the sheave,`or the rope may be endless andl secured at. one point to the sheave, sogthat` pulling on the" rope in the direction the right, and moving theV sheave in the-op posite direction willslacken theline. Qbviously, whatever the angular position ofthe sheave, .it may be turned easily by the rope. f i It. will now be plain thatall the above-V mentioned disadvantages .of using devices means ot such astackle for replacing dead-end in suiators are eliminated by employing thedescribed jack; but itY willgbe clear that the construction of my jackl may be variedy and yetac'complish the same results vand that its 2. In `combination withy'ajack. screw, a

clamp adapted tomount the jack on a cross arm ot a transmission line support, means connecting the clamp and ij ack whereby the latter may turn in two planes .after` the clamp is fixed, and means Jfor operating the jack from the base of the tower.

13. In combination `with a jack screw and a mounting therefor adapted to hold the jack upon a transmission line support adjacent the dead end of such Y ot the screw enabling it to be connected with fa wheel adapted` to operate the jack to take theloadbil the transmission` line,v and lexiblevmeans en easing turn the wheel in either direction from a distance. l" i i` i 1 4.` In combination with Vthe stickfhaving a hook at oneend, means connecting the other line, `means on one end the `wheel to.V enable an operator to end oizjthe stick wi'ththe transmission line rv i a rod having a clevis at-one-end engaged with said hook. said rod having threads, a casing'carrying'fa nut engagedwith said rod, and means forturningsaid nut onsaid rod. Y ^V' j Y 5.111' a jack, in combination, a hollow casing, a 'screw-threadedrod received within the casing but out otengagement therewith, Y

a nut revolubly mounted in the casing with las its threads engaginglthose of the rod, anda wheel detachably mounted on the nut so whatever its position relative to the clamp.

7. In a jack, in combination, a hollow Y casing, a thrust bearing in the casing, a nut between the bearing and casing and rotatably carried, a screw-threaded rod passing through the casing and engaging` the nut with its threads, means on one end of the rod whereby it may be engaged with a part to be pulled, means for rotating the nut, and means for supporting the casing so that it may rock in a horizontal plane as well as in a vertical plane.

8. In a jack having a screw threaded rod moved longitudinally by rotation ot a nut member with which its threads are engaged, a neck formed on said nut and having a radial lug, a sheave mountable upon the neck and having a slot to pass said lug, and a rib on the hub of the sheave en gageable with the lug when' the sheave is turned whereby rotation of the sheave causes similar movement of the nut.

9. In combination, a jack screw adapted to be used in changing dead end insulators, and a mounting therefor adapted to hold the jack upon an insulator support, said mounting including a clamp, a pin swiveled in the clamp, and means pivotally connecting the jack screw with one end of the pin.

lO. A jack screw having supporting means adapted to mount the jack on the cross arm of a transmision line support, said supporting means permitting swinging of the jack as a whole` in both horizontal and vertical l planes, said jack including a rotatable member and a longitudinally movable member, means on the latter member whereby the transmission line may be supported from said jack, and means engageable with the former member `for operating the jack.

' In testimony, that I claim the foregoing as my own, I have hereto aiiixed my signature. i

TOMLINSON FORT JOHNSON, JR. 

